I'm sorry but this is so sad me.

I get marriages do not work but I am so heartbroken for my friend. My best friend is in the marine corps in Japan right now and he is the sweetest guy I know, he married a girl five months ago who I have heard stories about but ignored because he loved her. Recently I received a FaceTime call from him saying that she wants to divorce him because her and her friend got a place and she wants to live her life, seemed very suspicious to me so I looked on her Instagram and she has a boyfriend a week after saying she wanted a divorce and is twerking all over him and stuff. I feel so bad for my friend but I think I should keep it to myself, it's not my place and I don't want him to stress if she's been cheating or anything like that cause being away from everyone you love is hard enough. Advice??